I. Field of the Invention
The present invention relates to data communication. More particularly, the present invention relates to novel and improved method and apparatus for testing wireless communication channels.
II. Description of the Related Art
Wireless communication systems such as code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, and others are widely used to provide various types of communication such as voice, data, and so on. For these wireless systems, it is highly desirable to utilize the available resources (i.e., bandwidth and transmit power) as efficiently as possible. This typically entails transmitting as much data to as many users within as short a time period as supported by the conditions of the communication links.
To achieve the above goal, the communication links between a transmitting source (e.g., a base station) and the receiving devices (e.g., “connected” remote terminals) within the system may be characterized. Based on the characterized link conditions for the remote terminals, the system may be better able to select a particular set of remote terminals to serve, allocate a portion of the available resources (e.g., transmit power) to each selected remote terminal, and transmit to each remote terminal at a data rate supported by the allocated transmit power and characterized link conditions.
Conventionally, a communication link is characterized by transmitting (e.g., from a base station) a known data pattern (e.g., generated by a defined pseudo-random number generator), receiving the transmitted data pattern, comparing the received data pattern with a locally generated data pattern to determine transmission errors, and reporting the results back to the transmitting source. This “loop-back” testing is typically performed continuously for a number of frames over the desired test interval. The test results are reflective of the performance of the communication link over that test interval.
Many newer generation wireless communication systems are capable of flexible operation. For example, data may be transmitted in bursts and over one or more traffic channels (or physical channels), the data rate may be allowed to vary from frame to frame, the processing of the data may also vary (e.g., from frame to frame and/or from channel to channel), and so on. The conventional loop-back test technique typically characterizes the communication link (e.g., one traffic channel) based on a defined set of test parameters, and may not provide an accurate assessment of the performance of the communication link when the system operates in this flexible manner.
As can be seen, techniques that can be used to characterize a communication link under various flexible operating conditions supported by a wireless communication system are highly desirable.